Acronym, standing for Titties by Default. Refers to the massive protrusions of fatty tissue present in the chest area of overweight women, and occasionaly men. Not to be confused with BAT's (bomb-ass titties), Titties by Default are not composed of breast tissue, but rather an inevitable dispersion of fat cells throughout the bodies of those afflicted. While TBD's are responsible for giving fat women a false sense of confidence and self worth, they are equally capable of deceiving unsuspecting onlookers, and masquerading as BAT's.

Tipsy borderline drunk. The familiarly affectionate period when you're having a good time but have yet to spewed on yourself/others, effectively wrecking their night. The potentially unfortunately period where you remember what you did enough to regret it. The period you aspire to, every time you go out (and somehow manage to surpass). The best feeling of all time.

Hungover: Big night?
Recovered: I was TBD, da best.
Hungover: Good times. I don't think I've ever been TBD. It's either one or the other.
Recovered: You're missing out. Gain some control, man.